Will, the BlackCandy's mysite/templates/page.ss contains the following code. There is one more </div>'s than needed and it prevents the template running in firefox. I'm removing the one found immediatley after $Layout it seems to work... can you republish this? :)
<div id="Container" class="typography">
<div id="Header">
<h1>Your Site Name</h1>
<p>your site's tagline here</p>
<% if Menu(1) %>
<% include Menu1 %>
<% end_if %>
</div>
<div class="br"><!-- --></div>
$Layout
</div>
<div class="br"><!-- --></div>
<% include Footer %>
</div>